The present invention relates to tissue bulking, the treatment gastroesophageal reflux disease, urinary incontinence and the amelioration of skin wrinkles.
Although gastroesophageal reflux is a normal physiological phenomenon, in some cases it is a pathophysiological situation that can result in a variety of symptoms which may become severe in extreme cases. Gastro-Esophageal Reflux Disease (xe2x80x9cGERDxe2x80x9d), describes a backflow of acidic and enzymatic liquid from the stomach to the esophagus. It causes burning sensations behind the sternum that may be accompanied by regurgitation of gastric acid into the mouth or even the lung. Complications of GERD which define the severity of the disease include esophageal tissue erosion, and esophageal ulcer wherein normal epithelium is replaced by a pathological tissue.
Statistical data indicate that about 35% of the American population suffer from heartburn at least once a month and between 5 to 10% once a day. More importantly for this kind of disease about 2% of the American population suffer from GERD based on medical evidence data from endoscopic examination. This disease is related to the age of individuals and seems to increase after 40 years of age. (Nebel O. T. et al., Am. J. Dig. Dis., 21(11):953-956 (1976)).
In normal patients, after a meal the lower esophageal sphincter remains closed, but in patients with GERD, it relaxes and allows some acidic material to reflux into the esophageal tube as a result of stomach contractions. Actually GERD can be attributed primarily to transient relaxation of the lower esophageal sphincter. In other cases, GERD can be attributed to decreased resting tone of the lower esophageal sphincter or to congenital small dimension of the sphincter itself. Other causes also exist which contribute to varying degrees to the existence and severity of this disease.
In addition, there are external factors that contribute to exacerbate the symptoms of GERD, which conditions include eating fatty foods, caffeine intake, smoking, tight clothing and certain medications. Decrease in salivation can also be a factor that exacerbates GERD, since under normal conditions saliva, which is an alkaline liquid, aids in neutralizing acidic reflux and therefore diminishing the duration of the acidic exposure of the esophagus.
Erythema is one of the first visible signs of GERD, which can be seen by endoscopy. Tissue erosion indicates more advanced disease which can then become deep ulcers and lead to cancer (adenocarcinoma increases in incidence faster than other types of cancer). Diffuse ulceration and specific complications occur in about 3.5% of patients less than 65 years of age with esophageal obstruction, blood loss, and in some cases, perforation. Ulcerative situations not only lead to complications, but they are also more resistant to treatments. Although severe complications are uncommon in young patients, they occur in about 20-30% of patients over 65 (Reynolds J. C, Am. J. Health-Sys. Pharm 53, (1996)).
Prior to the present invention, in an attempt to increase the function of the sphincter, bulking methods using bovine collagen and Teflon paste have been used in patients. Both methods have been unsuccessful, however, as these materials migrate over time from the initial site of implantation.
At present, GERD is generally managed by over-the-counter (xe2x80x9cOTCxe2x80x9d) antacids or prescription drugs, including proton pump inhibitors, motility agents and H2 blockers. In addition, a portion of GERD patients require surgical intervention; the most common type of surgery is fundoplication which can be done by conventional surgical techniques, or using laparoscopic techniques. However, fundoplication surgery carries the risk of serious side effects and is only marginally successful in curing GERD. Respiratory symptoms are also associated with GERD in about 50% of patients, and in patients undergoing fundoplication, these respiratory symptoms can even increase (76% reported in a study by Johnson W. E. et al., Archives of Surgery, 131:489-492 (1996)).
Urinary incontinence is a prevalent problem that affects people of all ages and levels of physical health, both in the community at large and in healthcare settings. Medically, urinary incontinence predisposes a patient to urinary tract infections, pressure ulcers, perineal rashes, and urosepsis. Socially and psychologically, urinary incontinence is associated with embarrassment, social stigmatization, depression, and especially for the elderly, an increased risk of institutionalization (Herzo et al., Ann. Rev. Gerontol. Geriatrics, 9:74 (1989)). Economically, the costs are astounding; in the United States alone, over ten billion dollars per year is spent managing incontinence.
Incontinence can be attributed to genuine urinary stress (urethra hypermobility), to intrinsic sphincter deficiency (xe2x80x9cISDxe2x80x9d), or both. It is especially prevalent in women, and to a lesser extent incontinence is present in children (in particular, ISD), and in men following radical prostatectomy.
One approach for treatment of urinary incontinence involves administration of drugs with bladder relaxant properties, with anticholinergic medications representing the mainstay of such drugs. For example, anticholinergics such as propantheline bromide, and combination smooth muscle relaxant/anticholinergics such as racemic oxybutynin and dicyclomin, have been used to treat urge incontinence. (See, e.g., A. J. Wein, Urol. Clin. N. Am., 22:557 (1995)). Often, however, such drug therapies do not achieve complete success with all classes of incontinent patients, and often results in the patient experiencing significant side effects.
Besides drug therapies, other options used by the skilled artisan prior to the present invention include the use of artificial sphincters (Lima S. V. C. et al., J. Urology, 156:622-624 (1996), Levesque P. E. et al., J. Urology, 156:625-628 (1996)), bladder neck support prosthesis (Kondo A. et al., J. Urology, 157:824-827 (1996)), injection of crosslinked collagen (Berman C. J. et al., J. Urology, 157:122-124 (1997), Perez L. M. et al., J. Urology, 156:633-636 (1996); Leonard M. P. et al., J. Urology, 156:637-640 (1996)), and injection of polytetrafluoroethylene (Perez L. M. et al., J. Urology, 156:633-636 (1996)).
A recent well known approach for the treatment of urinary incontinence associated with ISD is to subject the patient to periurethral endoscopic collagen injections. This augments the bladder muscle in an effort to reduce the likelihood of bladder leakage or stress incontinence.
Existing solutions to circumvent incontinence have well known drawbacks. The use of artificial sphincters for children with intractable incontinence requires long term surveillance of the urinary tract because of the potential for renal failure after device placement (Levesque P. E. et al., J. Urology, 156:625-628 (1996)). While endoscopically directed injections of collagen around the bladder neck has a quite high success rate in sphincter deficiency with no significant morbidity, the use of collagen can result in failures that occur after an average of two years and considerations need to be given to its cost effectiveness (Khullar V. et al., British J. Obstetrics and Gynecology, 104:96-99 (1996)). In addition, deterioration of patient continency, probably due to the migration phenomena (Perez L. M. et al.) may require repeated injections in order to restore continency (Herschorn S. et al., J. Urology, 156:1305-1309 (1996)).
The results with using collagen following radical prostatectomy for the treatment of stress urinary incontinence have also been generally disappointing (Klutke C. G. et al., J. Urology, 156:1703-1706 (1996)). Moreover, one study provides evidence that the injection of bovine dermal collagen produced specific antibodies of IgG and IgA class. (McCell and, M. and Delustro, F., J. Urology 155, 2068-2073 (1996)). Thus, possible patient sensitization to the collagen could be expected over the time.
Despite of the limited success rate, transurethral collagen injection therapy remains an acceptable treatment for intrinsic sphincter deficiency, due to the lack other suitable alternatives.
Damage to the skin due to aging or exposure to the sun and other elements often results in wrinkles and other skin anomalies. In order to remove wrinkles from the skin, people often resort to cosmetic surgery, such as face lifts and skin tucks. In addition, collagen injections have been used to remove or ameliorate skin wrinkles. Collagen injections have also been used for tissue bulking or to increase the fullness of certain body parts, e.g., to increase the fullness of lips or around the eyes and eyebrow area of the face. However, collagen is a naturally occurring substance which the body may enzymatically degrade and eliminate over time, thus requiring repeat treatments. Even more alarming from a cosmetic perspective, collagen may move from the initial site of injection, causing unsightly bumps and bulges under the skin at undesired locations.
Microbeads or solid microparticles have been used for the correction of skin wrinkles. For examples, silicone particles, TEFLON paste, collagen beads and polyacrylic microspheres have been used with disappointing results due to, inter alia, adverse tissue reactions, biological degradation and migration from the initial implantation location.
Prior to the present invention, microspheres have been manufactured and marketed for in vitro use in anchorage dependent cell culture. (Van Vezel, A. L., Nature, 216:64-65 (1967); Levine et al., Somatic Cell Genetics, 3:149-155 (1977); Obrenovitch et al., Biol. Cell., 46:249-256 (1983)). They have also been used in vivo to occlude blood vessels in the treatment of arteriovascular malformation, fistulas and tumors (See, U.S. Pat. No. 5,635,215, issued Jun. 3, 1997 to Boschetti et al.; Laurent et al., J. Am. Soc. Neuroiol, 17:533-540 (1996); and Beaujeux et al. J. Am. Soc. Neuroial, A:533-540 (1996)).
Further, direct implantation of cells into living tissues such as brain or liver to correct specific deficiencies has been attempted albeit with a number of failures. The major problems associated with direct cell transplantation are the long term viability of the cell transplant and the immunopathological as well as histological responses. Microparticles with cells attached on their surface have been used in some in vivo applications. Cherkesey et al., IBRO, 657-664 (1996), described the culture of adrenal cells on coated dextran beads and the implantation into mammalian brain to supplant some specific disorders related to 6-hydroxydopamine-induced unilateral lesions of the substantia nigra. The pre-attachment of cells to dextran microcarriers allowed for improved functions of the cells implanted into the brain. Also liver cells transplantation has been used to manage acute liver failure, or for the replacement of specific deficient functions such as conjugation of bilirubin or synthesis of albumin. For this purpose, an intrasplenic injection of hepatocytes grown on the surface of microspheres was performed (Roy Chowdhury et al., in: Advanced Research on Animal Cell Technology, AOA Miller ed., 315-327, Kluers Acad. Press, 1989).
Most of cell implant results have been, however, largely disappointing for the designated functions (or have had low levels of biological function).
The present invention encompasses the use of implantable microparticles in the treatment of GERD, urinary incontinence and skin wrinkles. In each use the particles are implanted into the appropriate tissue, muscle, organ etc. as a bulking agent. Further, in each use the microparticles are preferably pre-coated, with autologous cells, for example, muscle cells, fat cells and the like. The microparticles of the invention are biocompatible non-toxic polymers coated with, linked to or filled with cell adhesion promoters. The microparticles preferably contain a positive charge on their surface by way of a cationic monomer or polymer.
In one embodiment, the invention encompasses the treatment of gastroesophageal reflux disease in a human which comprises implanting hydrophilic biocompatible microparticles comprising (a) a positive charge and a cell adhesion promoter; and (b) autologous cells layered on the surface of said beads, into the lower esophageal sphincter. The microparticles are preferably microspheres or microbeads which are described in detail herein. The autologous cells are preferably taken from the area where the implantation is to be made. Serum or whole blood taken from the patient can be used to wash the microparticles prior to implantation. For GERD treatment implantation may also be made by using standard techniques known to the skilled artisan, such as injection (or injections) via syringe or other suitable devices.
In yet another embodiment, the invention encompasses the treatment of urinary incontinence in a human which comprises implanting hydrophilic biocompatible microparticles comprising (a) a positive charge and a cell adhesion promoter; and (b) autologous cells layered on the surface of the beads, into the urinary sphincter. The microparticles are preferably microspheres or microbeads as described herein. Further, the autologous cells are preferably taken from the area where the implantation is to be made. Serum or whole blood from the patient can be used to wash the microparticles prior to implantation. Implantation is generally made using a syringe or other device suitable for the particular tissue of implantation.
In another embodiment, the invention encompasses a method of treating skin wrinkles in a human which comprises the administration or implantation of microparticles comprising a hydrophilic copolymer having a positive charge, and a cell adhesion promoter, which microparticles have been pre-treated with autologous cells. The microparticles can be simply exposed to the autologous cells or mixed thoroughly with autologous cells prior to implantation.
It should be recognized that both treatments for GERD and urinary incontinence described above can be used in combination with conventional therapies now used to treat these diseases i.e., oral diuretics, antacids, suitable drug therapy and the like. Such combination therapy can lead to a faster, safer and more comfortable recovery for the patient.
In yet another embodiment, the invention encompasses the treatment or amelioration of skin wrinkles which comprises administering hydrophilic biocompatible microparticles comprising: (a) a positive charge and a cell adhesion promoter; and (b) autologous cells, collagen, collagen derivatives or glucosaminoglycans layered on the surface of the beads, into the area of or surrounding the skin wrinkles. In other words, microspheres or microbeads coated with a cell adhesion promoter and pre-treated with the appropriate tissue bulking cells, are administered to the area of treatment.
As used herein the terms xe2x80x9cadministeredxe2x80x9d, xe2x80x9cimplantedxe2x80x9d, or xe2x80x9cimplantationxe2x80x9d are used interchangeably and mean that the material is delivered to the area of treatment by techniques know to those skilled in the art and appropriate for the disease to be treated. Both invasive and non-invasive methods may be used for delivery.